These distros are pretty much identical aside from the fact that Ubuntu installed with Unity and Mint installed with Cinnamon. First impressions make me lean back towards Ubuntu, which kind of annoys me because Mint feels more like what Linux should be and Ubuntu has a sudo-Apple feel to it with its music store and cloud service immediately in my face. Do I want to get involved in yet another cloud service and music store? No not really. My plans were to stay with Google and Amazon for pretty much all my media purchases going forward. I've been pretty impressed with Google Play and the latest version of iTunes didn't impress me much.
Neither had out of the box support for my wireless hardware which is typical but also disappointing. I suppose most people switching to Linux are coming from Windows and not Mac so it kind of makes sense not to drop immediate support for that on the install disc. Still, I wish it was there, but from what I've researched it may be an easy fix once I'm hardwired in.
Ubuntu/Unity felt quicker and didn't spin my fans up like crazy. It seemed to have better control of my Macbook in general.
Mint/Cinnamon gave me the kind of screen real estate I wanted, aside from the two desktop icons. I never attempted to remove them but I prefer my desktop to be void of any icons. Mint also seemed more robust and it certainly had more settings to tweak, which for me is good. I like control.
So maybe a Mint/Mate and OpenSuse install tomorrow.